Elmer Robinson

Gaseous Nitrogen Compound Pollutants from Urban and Natural Sources

Major aspects of the circulation through the atmospheric environment of a number of gaseous nitrogen pollutants have been estimated, including source magnitudes, residual atmospheric concentrations...

Carbon Monoxide in the Atmosphere

A carbon monoxide analyzer has been developed which is capable of continuous measurement of the carbon monoxide concentration in the atmosphere. The operating principle of the instrument is the reaction of carbon monoxide with hot mercuric oxide followed by the photometric determination of the mercury vapor produced. Oxygenated hydrocarbons and olefins are quantitatively detected. Those normally present are in the ambient atmosphere in low concentrations relative to CO. Hydrogen and methane in the atmosphere do not interfere with the CO analysis. Measurements of atmospheric CO concentrations in California, Greenland, and Oregon seem to indicate that CO content is an air mass characteristic. North Pacific marine air mass concentrations may be as low as about 0.040 parts per million (ppm) CO, while the air mass over continental California seems to be characterized by CO levels of 0.5-1.0 ppm or greater.

Gaseous Sulfur Pollutants from Urban and Natural Sources

Major aspects of the circulation through the atmospheric environment of sulfur pollutants have been estimated, including source magnitudes, residual atmospheric concentrations, and scavenging processes. The compounds considered include SO2 and H2S, as well as sulfates. One-third of the sulfur reaching the atmosphere comes from pollutant sources, mainly as SO2. Within the atmosphere there is a net transfer of sulfur from land to ocean areas. Pollutant sources annually amount to 73 × 106 tons as sulfur while natural sources amount to 142 × 106 tons, mainly as H2S and sulfate sea spray. More than two thirds of the natural and pollutant sulfur emissions occur in the northern hemisphere. When only pollutant emissions are considered, 93 per cent occur in the northern hemisphere.

Gaseous Atmospheric Pollutants from Urban and Natural Sources

Major aspects of the circulation through the atmospheric environment of a number of gaseous pollutants have been estimated, including source magnitudes, residual atmospheric concentrations, and scavenging processes. The compounds considered include the major sulfur and nitrogen pollutants as well as CO. One-third of the sulfur reaching the atmosphere comes from pollutant sources, mainly as SO2. Within the atmosphere there is a net transfer of sulfur from land to ocean areas. In the global atmospheric nitrogen cycle, pollutant emissions of NO2 play only a minor role, and the atmospheric nitrogen cycle is apparently dominated by natural emissions of ammonia. Scavenging mechanisms for removing CO from the atmosphere are very speculative, but there is now considerable evidence of an oceanic source of natural CO to add to the very large pollutant source.

Particle size distribution of urban lead aerosols.

Size distributions of lead aerosols were obtained for 61 test periods in five urban and two remote areas of the United States. The tests were carried out under a variety of weather conditions in downtown, industrial, and residential locations of Los Angeles, the San Francisco Bay area, Chicago, Cincinnati, Philadelphia, and remote sites in Oklahoma and Arizona. Samples were obtained with a modified Goetz Aerosol spectrometer. Various fractions of the collected samples were analyzed by the dithizone method for lead and the size distributions were calculated on the basis of the chemical determinations. Size distributions were generally similar at the several sampling sites covered in the study.

Size distribution of sulfur-containing compounds in urban aerosols.

Abstract An aerosol spectrometer was used to determine the size distribution of sulfur-containing particulate materials in urban areas of northern and southern California. Based on a limited number of summer daytime samples, a typical Menlo Park size distribution had a mass median diameter of about 0.3 μ with upper and lower quartiles at about 0.9 and 0.1 μ, respectively. A typical Pasadena size distribution would be about one-tenth micron larger. The diameters given are for equivalent unit-density spheres of the same settling velocities as the sampled particles.

Variations in the size distributions of sulfur-containing compounds in urban aerosols☆

Abstract A program of aerosol collection was conducted with the Goetz Aerosol Spectrometer in the Los Angeles and San Francisco Bay areas during the spring and summer of 1964 and 1965. These collections yielded more than seventy individual size distributions of sulfurcompound particulates. Weighted averages, calculated from the individual collections, are presented for data classified according to humidity, time of day, and location. A typical size distribution for all the data would have a mass median equivalent diameter of about 0.35 μ with upper and lower quartiles at about 1.0 and 0.1μ, respectively. Sulfur-compound aerosols collected during periods of high humidity had a substantially higher average mass median diameter than those collected under low humidity conditions. A limited number of round-the-clock samples indicated that the average size of the particles generally was largest in the forenoon, decreased in the afternoon and evening, and then increased again during the early morning. There was some variability among the average size distributions for different sampling locations.

Size Distribution Studies with the Aerosol Spectrometer

It is shown how the Goetz Aerosol Spectrometer can be used to determine the particle size distribution of a specific component of a mixed atmospheric aerosol. The method requires no micrographic counting, but does require that sensitive quantitative chemical analysis methods be available for the compounds of interest. The accuracy of the method and the sensitivity limitations are briefly discussed.

Low-Level Temperature Structure under Alaskan Ice Fog Conditions

Wiresonde temperature soundings were taken during two winters at Eielson Air Force Base, near Fairbanks, Alaska, as part of an ice fog investigation. Correlations were found between the depths of the visible fog layers and the steep portions of the temperature inversions. The steep portions of the temperature inversions were usually confined to the lowest 100 feet of the atmosphere. The frequency of occurrence of strong surface inversions was less than had previously been expected for an arctic continental area with temperatures in the vicinity of −40C. This is attributed to the modifying effect of the ice fog, which was usually present in the observation area at temperatures below −30C.

Some Air Pollution Aspects of the Los Angeles Temperature Inversion

During research on air pollution in Los Angeles, various meteorological aspects of the problem have been studied. One of these was the derivation of a mathematical formula which combines measures of the stability, height, and thickness of the inversion layer to give an overall value for its intensity. This formula has been useful in describing inversions and in various correlation studies. A file of data on inversion conditions in the Los Angeles area has been accumulated in the course of the smog program. These data, which apply to mean inversion conditions from May through November, are interesting not only for the smog problem but also in evaluating the climate of the area. They should prove useful in other studies where an appreciation of the climatic nature of the inversion surface is required. The cycle of the inversion indicates that the base gradually lowers during the summer and early fall and that as early as June, inversions are present 90% of the time. The “smog season” generally coincides wit...